Running 360/360 @ 20 PSI on my stock block (was 385/370 @ 22 PSI before i added a cat) with a .82 GT30R ... alot depends on what safety mods you have in addition to your power mods. Never had a hiccup. I have a lot of safety mods though. Keep in the intake temps cool and boost under control and that helps a lot. So I am not too much over 350, but have had a compression test and Blackstone labs test and both came back perfect.